I thought some could have a hard time deciding as I did so here is my feedback for what its worth.
I am no tech expert, just a 3D artist (modeler) and occasional gamer.
Basically I feel these cards performance is very close so the choice is not simple.

the system is macpro 4.1 2,93 / 8gb RAM / SSD drive
I used osx 10.8.3 and win 7 64bit with latest drivers from nvidia and AMD

Gaming
only games I could run are sleeping dogs and dishonored which unfortunatelty are not the most demanding, so I could hardly feel any difference.
dishonored (max settings) feels a little more fluid with GTX670 but it is very close.
EDIT : just tried Batman arkham city which is a much more demanding game.
with max settings, the performance is at GFX670 advantage by a small but clear margin.
The game uses PhysX engine which is nvidia exclusive so it probably helps the framerate.
few games use the technology so it is again probably not the best benchmark.

3D work
maya 2012
very similar viewport performance with both cards.

mudbox 2013
again performance is quite similar, hd7950 feel slightly faster, nothing very obvious.
as a reference default head smoothed to 32 million polygons is slightly laggy with both cards, yet very confortable to work. you can easily work up to maybe 70/80 million
Subdividing model is faster with HD7950
EDIT : for some reason mudbox preview shadows are not working with GTX670 with windows7, they are working with osx but the quality is poor (similar to GT120), HD7950 shadows look good with both systems.

Zbrush
zbrush doesn't rely on GPU much so performance is similar.

if you need CUDA cores (octane/AE...) the choice will be obvious, only nvidia supports it.

sound levels
GTX670 is much more quiet.
idle is silent (similar to GT120), it can be noisy but not as much and less often than HD7950
HD7950 can get quite loud (it does each startup) but when idle or regular use noise is reasonnable, still it is the most noticeable noise in the system.

temperatures
hd7950 blows hot air (outside the case) and the plastic cover quickly gets very hot.
asus cooling system is way better, the heat is contained in the metal pipes mostly,
the air is not hot so the fact it is blown inside the case is not a concern.

there is no winner here, it depends on your priorities.
Opengl is the most important criteria to me but I am actually sending back the HD7950 as I like my system to be quiet being used to the silent GT120 and macbook.
the performance difference seemed slight to me in real use, despite what cinebench benchmark is saying (not sure this old benchmark is any good actually)

Remember that if the warranty is not critical to you, you can always replace the 7950 cooler with a different one.

You would need the usual thermal paste remover (Arcti Clean is it?), some Arctic Silver paste and either some thermal pads or thermal epoxy. I did it with my stock 5870 and have been very happy with the results over the past two years.

Remember that if the warranty is not critical to you, you can always replace the 7950 cooler with a different one.

You would need the usual thermal paste remover (Arcti Clean is it?), some Arctic Silver paste and either some thermal pads or thermal epoxy. I did it with my stock 5870 and have been very happy with the results over the past two years.

good to know! I wasn't aware such cooling systems were available.
Could change my deicision actually, I will do some research thanks

In short, you can choose any make of third-party cooler for the 7950 provided you have the spare space above the main GPU slot. Do a bit of reading to get a shortlist of suitable coolers then ask for opinions on the forum.

Nice write up, thanks! But a question.... You have the positive attribute concerning price going to the GTX670? Is this a mistake? I dunno where you are but here in Japan (just went to the shops today) the 7950 is $200 new and the 670 is about $350 on average.

To give you an idea of the process so you can decide if you want to tackle the mod, here is my review of the appropriate cooler for the stock apple 5870 I did two years ago.

very nice !
after more testing with mudbox it seems the difference is really irelevant and I'm using it 90% of the time so I'll stick to the gtx670 anyway.

Quote:

Originally Posted by Tesselator

Nice write up, thanks! But a question.... You have the positive attribute concerning price going to the GTX670? Is this a mistake? I dunno where you are but here in Japan (just went to the shops today) the 7950 is $200 new and the 670 is about $350 on average.

the 7950 I got is the new mac edition which is much more expensive than the PC version.
I got it for 440€, while the pc version is around 270€ here in France.
the only advantage you'll get over the pc version is the bootscreen is working.
the asus gtx670 was 370€

the 7950 I got is the new mac edition which is much more expensive than the PC version.
I got it for 440€, while the pc version is around 270€ here in France.
the only advantage you'll get over the pc version is the bootscreen is working.
the asus gtx670 was 370€

nothing special, drivers are included in 10.8.3
you just need a couple 6pin to 6pin mini power cables which where not provided (they are with the sapphire)
I also used a minidisplayport->displayport adapter so I could plug my cinema display.

I'm a 3d person myself, so its great to see the cards tested in a context I care about.

The extra GB of Vram has weight in the decision to me also me. (7950 3gb vs 670 2gb)

Wish the K5000 cost less, or ATI made a W7000 mac edition.

you're welcome,
as a 3D artist depending what you're doing the extra vram can be interesting or will not have any effect at all.
Still I think the simple fact you know you can run a few applications safely is a good selling point.
Especially if those are vram hungry, for texturing needs for example as we're now used to work with multiple 4k maps on a single character.

As for me as a modeler I probably don't have the need for it 95% of the time so it didn't have any impact through the quick testing I did, but the day I'll get back to some texturing I guess I'll be happy to have that extra 1gb.

I thought some could have a hard time deciding as I did so here is my feedback for what its worth.
I am no tech expert, just a 3D artist (modeler) and occasional gamer.
Basically I feel these cards performance is very close so the choice is not simple.

the system is macpro 4.1 2,93 / 8gb RAM / SSD drive
I used osx 10.8.3 and win 7 64bit with latest drivers from nvidia and AMD

Gaming
only games I could run are sleeping dogs and dishonored which unfortunatelty are not the most demanding, so I could hardly feel any difference.
dishonored (max settings) feels a little more fluid with GTX670 but it is very close.
EDIT : just tried Batman arkham city which is a much more demanding game.
with max settings, the performance is at GFX670 advantage by a small but clear margin.
The game uses PhysX engine which is nvidia exclusive so it probably helps the framerate.
few games use the technology so it is again probably not the best benchmark.

3D work
maya 2012
very similar viewport performance with both cards.

mudbox 2013
again performance is quite similar, hd7950 feel slightly faster, nothing very obvious.
as a reference default head smoothed to 32 million polygons is slightly laggy with both cards,
Subdividing model is faster with HD7950
EDIT : for some reason mudbox preview shadows are not working with GTX670 with windows7, they are working with osx but the quality is poor (similar to GT120), HD7950 shadows look good with both systems.

Zbrush
zbrush doesn't rely on GPU much so performance is similar.

if you need CUDA cores (octane/AE...) the choice will be obvious, only nvidia supports it.

sound levels
GTX670 is much more quiet.
idle is silent (similar to GT120), it can be noisy but not as much and less often than HD7950
HD7950 can get quite loud (it does each startup) but when idle or regular use noise is reasonnable, still it is the most noticeable noise in the system.

temperatures
hd7950 blows hot air (outside the case) and the plastic cover quickly gets very hot.
asus cooling system is way better, the heat is contained in the metal pipes mostly,
the air is not hot so the fact it is blown inside the case is not a concern.

there is no winner here, it depends on your priorities.
Opengl is the most important criteria to me but I am actually sending back the HD7950 as I like my system to be quiet being used to the silent GT120 and macbook.
the performance difference seemed slight to me in real use, despite what cinebench benchmark is saying (not sure this old benchmark is any good actually)

....temperatures
hd7950 blows hot air (outside the case) and the plastic cover quickly gets very hot.
asus cooling system is way better, the heat is contained in the metal pipes mostly,
the air is not hot so the fact it is blown inside the case is not a concern.

That is exactly backwards criteria for a cooling system. A cooling system should get rid of the heat not retain it closer to the primary heat producing elements.

More heat trapped in the heat pipes next to the GPU is not "way better". At least not in any thermodynamics sense.

Blowing hot air directly out of the box is better. The other "happens to work" because other fans are cleaning up the mess. For typical "create hurricane Katrina and hope it all works out" PC designs it will happen to work. But a cooling system that will re-injest some of the hot air it just expelled is not going to be efficient. You are actually lower the spread of the temperate gradient which leads to less efficient thermodynamics.

That is exactly backwards criteria for a cooling system. A cooling system should get rid of the heat not retain it closer to the primary heat producing elements.

More heat trapped in the heat pipes next to the GPU is not "way better". At least not in any thermodynamics sense.

Blowing hot air directly out of the box is better. The other "happens to work" because other fans are cleaning up the mess. For typical "create hurricane Katrina and hope it all works out" PC designs it will happen to work. But a cooling system that will re-injest some of the hot air it just expelled is not going to be efficient. You are actually lower the spread of the temperate gradient which leads to less efficient thermodynamics.

In theory I would agree with you but it seems temperatures are lower by reviews I have been reading, though I didn't verify myself (heaven gives same temperature but I am not sure it is the most appropriate benchmark).
once again the air is cold, so the other fans are not "cleaning up the mess" in any way and there is no worry at all for the hard drives above

Finally installed an arctic cooler accelero xtreme 7970 cooling system on the sapphire 7950.
this system is designed for 7970 and 7950 cards.
big thanks to danielcoffey for the great suggestion

I am very happy with the modification, the gpu is now cooler (35°C idle, 55°C full load) and the card is TOTALLY silent
The only fan you can hear go faster at full load is the front case fan, quite a relief after switching from GT120 to the noisy Sapphire system. I couldn't be more happy with my system now

Installation is easy as long as you are careful and don't rush,
it takes some time as the thermal paste take hours to dry.

I must specify I had to make a modification on the front fan unit so the card would fit in the case, I simply cut the plastic "slots" with 1-4 numbers on it so I gain a few centimers. It was necessary to remove them as the system is significantly longer than stock cooling system.
I am talking of the "slots you can see here hiding the fan.
The modification doesn't affect the fan function as these were in the way of the air so the airflow actually gets improved.
Removing the whole fan unit is not an option as it plays a crucial role in cooling the card PCB which can get very hot
so if you want that cooling system you have to do it. you can always buy a new fan unit on the internet the day you want to sell the mac pro they are easy to find so I didn't care myself.

One other thing is if you mount the system exactly as the manual you won't be able to install it on Slot1 as the gpu bottom plate is too far from the PCB (see here: http://www.expreview.com/img/review/...us_7970_15.JPG )
It is too thick to allow the card to be plugged due to the very close case element.
If you mount it like this you will be forced to install on higher slot, the fans will blow right to the hard drives (they nearly touch them) , not a good option IMO.

If you want to install it on slot1 you will only need to make the plate closer to PCB by not installing the 4 little black plastic tubes (shown on the right of this picture : http://upload.hardver-teszt.hu/imgs/...e-7970-3-b.jpg ) and then be very carefull not to tighten the screws too much to avoid any contact between the plate and the PCB, I have a few millimeters separation space left and the card is right as it is supposed to be on slot1
Of course don't forget to install the supplied foam isolation piece!

I also should mention I installed it on a macpro 4.1 so I have no idea if the info applies to older mac pros and if it fits or not.

I must specify I had to make a modification on the front fan unit so the card would fit in the case, I simply cut the plastic "slots" with 1-4 numbers on it so I gain a few centimers. It was necessary to remove them as the system is significantly longer than stock cooling system.
I am talking of the "slots you can see here hiding the fan.
The modification doesn't affect the fan function as these were in the way of the air so the airflow actually gets improved.
Removing the whole fan unit is not an option as it plays a crucial role in cooling the card PCB which can get very hot
so if you want that cooling system you have to do it.

Did you try pushing the little grey button to allow the fan assembly to slide backwards to install?

It is designed to do this and of all the 1000's of video cards I have played with I have never had to cut anything like that.

Did you try pushing the little grey button to allow the fan assembly to slide backwards to install?

It is designed to do this and of all the 1000's of video cards I have played with I have never had to cut anything like that.

Of course I did
The central part of the fan ( the one I had to remove) don t slide if you push the button, only the rest slides so it doesn t help at all
I m glad to hear you didn t have issues with any of the 1000s cards you ve played with
I guess you have experience with stock cards which of course would better not be that long for obvious reasons.
This is not a stock cooling system and it is known to be very long and not fit many cases. You'll see plenty of warnings and mention of these issues with arctic cooling GPU fans if you do a little search

As a good example the one i received was indeed a bit damaged at the end... It seems the shop sent me a refurnished item someone tried to push a little too hard to fit in his case. very annoying though I didn t bother sending it back as the damage is not important and wont affect performance.

I took a picture comparing the stock cooler and the arctic cooling,
as you can you see the arctic cooling is way longer than the already long card, if you check the gpu position you'll notice it is even placed a bit higher than the other.
You can see the damaged part I mentioned on the bottom left.

I need a newer graphics card because Realflow and Houdini are showing issues with my current card (The ATI HD 5870). I hate to drop the money on a card but between RealFlow's Hybrido not playing nice and Houdini freezing on shaded view of replicated curves with the Radeon 5870 I think its time to upgrade.